Sensitive quantification of trace zinc in water samples by adsorptive stripping voltammetry

A simple and sensitive adsorptive stripping voltammetry method was developed for determination of Zn using N-nitrozo-N-phenylhydroxylamine (cupferron) as a selective complexing agent. This complex absorbed on the hanging mercury drop electrode and created a sensitive peak current. The peak current and concentration of zinc accorded with a linear relationship in the range of 0.85–320 ng mL⁻¹. The influence of pH and the nature of supporting electrolytes, concentration of ligand, preconcentration time and applied potential were investigated. The relative standard deviation at a concentration level of 50 ng mL⁻¹ was 1.8%. The method was applied to the determination of zinc in city, river and mineral water samples, with satisfactory results.